Dye composition for keratinic fibres containing sulfured metaphenylenediamines, dyeing process and new sulfured metaphenylenediamines and preparation method thereof

ABSTRACT

The invention relates to a dye composition for keratinic fibers comprising an oxidation colorant precursor of the type ortho and/or para and a sulfured metaphenylenediamine having formula (I) ##STR1## wherein Z is alkyl, aralkyl, monohydroxyalkyl or polyhydroxyalkyl, aryl or aminoalkyl, as well as the acid salts thereof, with the condition that R 1  and R 2  do not represent simultaneously hydrogen when Z is alkyl or hydroxyalkyl, as well as the acid salts corresponding to the compounds of formula (I).

This is a continuation of application Ser. No. 08/133,051, filed asPCT/FR93/00148, Feb. 12, 1993, abandoned.

The present invention relates to new dyeing compositions for keratinousfibers containing sulfur-containing meta-phenylenediamines, to a processfor dyeing in alkaline medium using these compositions, to newsulfur-containing meta-phenylenediamines as well as to a process forpreparing them.

Sulfur-containing derivatives of aromatic amines have already been used,combined with oxidation dye precursors, in the presence of an oxidizingagent and alkali metal salts in acidic, neutral or basic medium fordyeing keratinous fibers. Such compositions are described in patent DE593 061.

It is known to dye keratinous fibers and in particular human hair, withdyeing compositions containing oxidation dye precursors and couplers.DE-A-3,343,642 describes such compositions containing, as coupler, a6-hydroxyalkylthio-1,3-diaminobenzene.

Couplers, also called color modifiers, make it possible to vary theshades obtained with oxidation dye precursors.

In the field for dyeing keratinous fibers and in particular human hair,couplers are being searched for which, combined with oxidation dyeprecursors, make it possible to obtain a broad range of shades, whileconferring in the hair a color having a satisfactory resistance tolight, to washing, to adverse weather conditions, to perspiration and tothe various treatments to which the hair may be subjected.

The applicants have just discovered, and this constitutes the subject ofthe invention, that the use of sulfur-containing meta-phenylenediaminesof formula (I) as coupler with ortho and/or para type oxidation dyeprecursors makes it possible to obtain, at neutral, acidic or alkalinepH, after application to the keratinous fibers and in particular humanhair, a broad range of shades of color exhibiting a particularlyremarkable resistance to light, to washing, to adverse weatherconditions, to perspiration and to the various treatments to which thehair may be subjected.

One subject of the invention therefore consists of oxidative dyeingcompositions intended to be used for dyeing keratinous fibers and inparticular human hair, containing at least one ortho and/or para typeoxidation dye precursor and at least one sulfur-containingmeta-phenylenediamine of formula (I) below.

Another subject of the invention is the process for dyeing keratinousfibers and in particular human hair, using such a composition mixed withan oxidizing agent.

The subject of the invention is also new sulfur-containingmeta-phenylenediamines as well as a process for preparing them and theiruse in dyeing compositions for keratinous fibers. Other subjects of theinvention will emerge on reading the following description and examples.

The subject of the present invention is therefore the dyeingcompositions for keratinous fibers and in particular human hair,containing, in a medium suitable for dyeing, at least one ortho and/orpara type oxidation dye precursor and at least, as coupler, onesulfur-containing meta-phenylenediamine of formula: ##STR2## in which: Zrepresents a C₁ -C₁₈ alkyl radical, an aralkyl radical in which thealkyl radical corresponds to C₁ -C₆, a monohydroxy (C₁ -C₆ alkyl) orpolyhydroxy (C₂ -C₆ alkyl) radical, an aryl radical, an aminoalkylradical of formula: ##STR3## in which n is an integer between 1 and 6inclusive, R₃ and R₄, which are identical or different, represent ahydrogen atom or C₁ -C₄ alkyl, hydroxy(C₁ -C₄ alkyl) or C₂ -C₆ acylradical; R₁ and R₂, which are identical or different, represent ahydrogen atom, a C₁ -C₆ alkyl radical, a monohydroxy (C₁ -C₆ alkyl),polyhydroxy(C₂ -C₆ alkyl), monocarbamyl (C₁ -C₆ alkyl), dicarbamyl(C₁-C₆ alkyl), amino(C₁ -C₆ alkyl), C₂ -C₆ acyl, C₂ -C₆ carbalkoxy,carbamyl or mono(C₁ -C₆ alkyl)carbamyl radical, with the proviso that R₁and R₂ do not simultaneously designate a hydrogen atom when Z designatesan alkyl or hydroxyalkyl radical, as well as the acid saltscorresponding to the compounds of formula (I).

Among the preferred meanings of the Z radical in the sulfur-containingmeta-phenylenediamines of general formula (I) according to theinvention, the C₁ -C₁₈ alkyl radical designates methyl, ethyl, propyl,butyl, dodecyl or hexadecyl radicals; the aralkyl radical designates thebenzyl radical; the mono- or polyhydroxyalkyl radical designates --CH₂--CH₂ OH, --CH₂ --CHOH--CH_(2--OH), --CH₂ --CHOH--CH₃ ; the aryl radicaldesignates phenyl; the aminoalkyl radical designates --CH₂ --CH₂ --NH₂ ;##STR4## --CH₂ --CH₂ --NHCH₃ ; --CH₂ --CH₂ --NHCOCH₃ ; when the R groupsrepresent an acyl radical, the latter preferably designates formyl,acetyl and propionyl radicals.

The acid salts corresponding to the sulfur-containingmeta-phenylenediamine compounds of general formula (I) are preferablychosen from the hydrochlorides, the sulfates or the hydrobromides.

Among the sulfur-containing meta-phenylene-diamines of general formula(I), the particularly preferred compounds are:

6-methylthio-1,3-diβ-hydroxyethylamino)benzene

6-methylthio-1-N-(β-hydroxyethylamino-3-aminobenzene

6-(β-acetylaminoethylthio)-1,3-diaminobenzene

6-methylthio-3-N-β-hydroxyethylaminoaniline

6-methylthio-3-acetylaminoaniline

6-(β-acetylaminoethylthio)-3-acetylaminoaniline

6-(β-acetylaminoethylthio)-3-amino-1-acetylamino-benzene

and their salts.

The compounds of formula (I) can be used as coupler in the presence ofortho and/or para type oxidation dye precursors known per se, which makeit possible to dye the hair by oxidative dyeing, according to a processusing a reaction of oxidative condensation of the precursors with thecoupler.

The ortho or para type dye precursors are compounds which are not dyesper se, but which form a dye by a process of oxidative condensation,either with themselves, or in the presence of a coupler or modifier.

These ortho or para type oxidation dye precursors are benzene orheterocyclic compounds comprising two amino or amino and hydroxyfunctional groups in the ortho or para position with respect to eachother.

The ortho or para type oxidation dye precursors may be chosen frompara-phenylenediamines, paraaminophenols, para heterocyclic precursorsderived from pyridine or pyrimidine, such as 2,5-diaminopyridine,2-hydroxy-5-aminopyridine, 2,4,5,6-tetraaminopyrimidine,4,5-diamino-1-methylpyrazole, 2-dimethylamino-4,5,6triaminopyrimidine,ortho-aminophenols and the so-called "double" bases.

As para-phenylenediamines, there may be mentioned more particularly thecompounds corresponding to the formula (III): ##STR5## in which: R₆, R₇,R₈, which are identical or different, represent a hydrogen or halogenatom, an alkyl radical, an alkoxy radical, a carboxy, sulfo orhydroxy(C₁ -C₄ alkyl) radical; R₉ and R₁₀, which are identical ordifferent, represent a hydrogen atom, an alkyl, hydroxyalkyl,alkoxyalkyl, carbamylalkyl, mesylaminoalkyl, acetylaminoalkyl,ureidoalkyl, carbalkoxyaminoalkyl, sulfoalkyl, piperidinoalkyl ormorpholinoalkyl radical or a phenyl radical optionally substituted inthe para position by an amino group, or alternatively R₉ and R₁₀ form,together with the nitrogen atom to which they are attached, a piperidinoor morpholino heterocycle, provided that R₆ or R₈ represents a hydrogenatom when R₉ and R₁₀ do not represent a hydrogen atom, as well as thesalts of these compounds. These alkyl or alkoxy groups have 1 to 4carbon atoms and especially designate the methyl, ethyl, propyl, methoxyand ethoxy radical.

Among the compounds of formula (III), there may be mentioned moreparticularly para-phenylenediamine, p-toluylenediamine,methoxyparaphenylenediamine, chloro-paraphenylenediamine,2,3-dimethylparaphenylenediamine, 2,6-dimethylparaphenylenediamine,2,6-diethylparaphenylenediamine, 2,5-dimethylparaphenylenediamine,2-methyl-5-methoxyparaphenylenediamine,2,6-dimethyl-5-methoxyparaphenylenediamine,N,N-dimethylparaphenylenediamine, N,N-diethylparaphenylenediamine,N,N-dipropylparaphenylenediamine, 3-methyl-4-amino-N,N-diethylaniline,N,N-di-(β-hydroxyethyl)paraphenylenediamine,3-methyl-4-amino-N,N-di(β-hydroxyethyl)aniline,3-chloro-4-amino-N,N-di(β-hydroxyethyl)aniline, 4-amino-N,N-(ethyl,carbamylmethyl)aniline, 3-methyl-4-amino-N,N-(ethyl,carbamylmethyl)aniline, 4-amino-N,N-(ethyl, β-piperidinoethyl)aniline,3-methyl-4-amino-N,N-(ethyl, β-piperidinoethyl)aniline,4-amino-N,N-(ethyl, β-morpholinoethyl)aniline,3-methyl-4-amino-N,N-(ethyl, β-morpholinoethyl)aniline,4-amino-N,N-(ethyl, β-acetylaminoethyl)aniline,4-amino-N-(β-methoxyethyl)aniline, 3-methyl-4-amino-N,N-(ethyl,β-acetylaminoethyl)aniline, 4-amino-N,N-(ethyl,β-mesylaminoethyl)aniline, 3-methyl-4-amino-N,N-(ethyl,β-mesylaminoethyl)aniline, 4-amino-N,N-(ethyl, β-sulfoethyl)aniline,3-methyl-4-amino-N,N(ethyl, β-sulfoethyl)aniline,N-[(4'-amino)phenyl]-morpholine, N-[(4'-amino)phenyl]piperidine,2-hydroxyethylparaphenylenediamine, fluoroparaphenylenediamine,carboxyparaphenylenediamine, sulfoparaphenylenediamine,2-isopropylparaphenylenediamine, 2-n-propylparaphenylenediamine,hydroxy-2-n-propylparaphenylenediamine,2-hydroxymethylparaphenylenediamine,N,N-dimethyl-3-methylparaphenylenediamine, N,N-(ethyl,β-hydroxyethyl)paraphenylenediamine,N-(dihydroxypropyl)paraphenylenediamine,N-4'-aminophenylparaphenylenediamine, N-phenylparaphenylenediamine.

These para-phenylenediamines can be introduced into the dyeingcomposition either in the form of a free base or in the form of salts,such as hydrochloride, hydrobromide or sulfate.

Among the p-aminophenols, there may be mentioned p-aminophenol,2-methyl-4-aminophenol, 3-methyl-4-aminophenol, 2-chloro-4-aminophenol,3-chloro-4-aminophenol, 2,6-dimethyl-4-aminophenol,3,5-dimethyl-4-aminophenol, 2,3-dimethyl-4-aminophenol,2,5-dimethyl-4-aminophenol, 2-hydroxymethyl-4-aminophenol,2-(β-hydroxyethyl)-4-aminophenol, 2-methoxy-4-aminophenol,3-methoxy-4-aminophenol, 3-(β-hydroxyethoxy)-4-aminophenol,2-methoxy-methyl-4-aminophenol, 2-aminomethyl-4-aminophenol,2-β-hydroxyethylaminomethyl-4-aminophenol,2-ethoxy-methyl-4-aminophenol, 2-(β-hydroxyethoxy)methyl-4-aminophenol.

The so-called "double" bases are bis-phenylalkylenediaminescorresponding to the formula: ##STR6## in which: Z₁ and Z₂, which areidentical or different, represent hydroxyl or NHR₁₅ groups, where R₁₅designates a hydrogen atom or a lower alkyl radical;

R₁₂ and R₁₃, which are identical or different, represent either hydrogenatoms or halogen atoms or alternatively alkyl radicals;

R₁₁ and R₁₄, which are identical or different, represent a hydrogenatom, an alkyl, hydroxyalkyl or aminoalkyl radical whose amino residuemay be substituted; Y represents a radical chosen from the groupconsisting of the following radicals: ##STR7## in which n is an integerbetween 0 and 8 and m, q and p are integers between 0 and 4, it beingpossible for this base to exist also in the form of its addition saltswith acids.

The alkyl or alkoxy radicals indicated above preferably designate agroup having 1 to 4 carbon atoms and especially methyl, ethyl, propyl,methoxy and ethoxy.

Among the compounds of formula (IV), there may be mentionedN,N'-bis(β-hydroxyethyl)-N,N'-bis(4'-amino-phenyl)-1,3-diamino-2-propanol,N,N'-bis(β-hydroxyethyl)-N,N'-bis (4'-aminophenyl)ethylenediamine,N,N-bis(4-aminophenyl)tetramethylenediamine,N,N'-bis(β-hydroxyethyl)-N,N'-bis(4-aminophenyl)tetramethylenediamine,N,N'-bis(4-methylaminophenyl)tetramethylenediamine,N,N'-bis(ethyl)-N,N'-bis(4'-amino-3'-methylphenyl)-ethylenediamine.

Among the ortho-aminophenols, there may be mentioned more particularly1-amino-2-hydroxybenzene, 6-methyl-1-hydroxy-2-aminobenzene,4-methyl-1-amino-2-hydroxybenzene,4-acetylamino-1-amino-2-hydroxybenzene.

The dyeing compositions conforming to the invention may also contain, inaddition to the coupler corresponding to the formula (I) defined above,other couplers known per se, such as meta-diphenols, meta-aminophenols,meta-phenylenediamines different from those of formula (I) above,meta-acylaminophenols, meta-ureidophenols, meta-carbalkoxyaminophenols,α-naphthol, indole derivatives, couplers possessing an active methylenegroup such as the β-ketone compounds, pyrazolones.

Among these couplers, there may be more particularly mentioned2,4-dihydroxyphenoxyethanol, 2,4-dihydroxyanisole, meta-aminophenol,resorcinol monomethyl ether, resorcinol, 2-methylresorcinol,2-methyl-5-aminophenol, 2-methyl-5-N-(β-hydroxyethyl) aminophenol,2-methyl-5-N-(β-mesylaminoethyl) aminophenol ,2,6-dimethyl-3-aminophenol, 6-hydroxybenzomorpholine, 2,4-diaminoanisole, 2,4 -diaminophenoxyethanol, 6-amino-benzomorpholine,[2-N-(β-hydroxyethyl) amino-4-amino]-phenoxyethanol,2-amino-4-N-(β-hydroxyethyl) aminoanisole, (2,4 -diamino)phenyl-β-γ-dihydroxypropyl ether, 2,4-diaminophenoxyethylamine,1,3-dimethoxy-2,4-diaminobenzene, 1,3,5-trimethoxy-2,4-diaminobenzene,1-amino-3,4-methylenedioxybenzene, 1-hydroxy-3,4-methylenedioxybenzene,2-chloro-6-methyl-3-aminophenol, 2-methyl-3-aminophenol,2-chlororesorcinol, 6-methoxy-3-hydroxyethylaminoaniline,1-ethoxy-2-bis(β-hydroxyethyl) amino-4-aminobenzene,3-diethylaminophenol, 1,3-dihydroxy-2-methylbenzene,1-hydroxy-2,4-dichloro-3-aminobenzene,4,6-hydroxyethoxy-1,3-diaminobenzene,4-methyl-6-ethoxy-1,3-diaminobenzene, 4-chloro-6-methyl-3-aminophenol,6-chloro-3-trifluoroethylaminophenol, and their salts.

There may be added to these compositions, as is well known in the priorstate of the art, especially for the purpose of imparting a shade to orincreasing the shimmer of the colors provided by the oxidation dyeprecursors, direct dyes such as azo or anthraquinone dyes or the nitroderivatives of the benzene series.

The entire para and/or ortho type oxidation dye precursors, as well asthe couplers used in the dyeing compositions conforming to theinvention, preferably represent 0.3 to 7% by weight relative to theweight of the said composition. The concentration of sulfur-containingmeta-phenylenediamine compounds of formula (I) may vary between 0.05 and3.5% by weight of the total weight of the composition.

The dyeing compositions conforming to the invention also contain intheir preferred embodiment, anionic, cationic, non-ionic or amphotericsurface-active agents or mixtures thereof. Among these surface-activeagents, there may be mentioned alkyl benzenesulfonates, alkylnaphthalenesulfonates, sulfates, ether sulfates and sulfonates of fattyalcohols, quaternary ammonium salts such as trimethylcetylammoniumbromide, cetylpyridinium bromide, ethanolamides of optionallyoxyethylenated fatty acids, polyglycerolated fatty alcohols,polyoxyethylenated or polyglycerolated alkylphenols, as well aspolyoxyethylenated alkyl sulfates.

These surface-active agents are present in the compositions conformingto the invention in proportions of between 0.5 and 55% by weight, andpreferably between 2 and 50% by weight relative to the total weight ofthe composition.

These compositions may also contain organic solvents for solubilizingthe components which may not be sufficiently soluble in water. Amongthese solvents, there may be mentioned by way of example, C₁ -C₄ loweralkanols such as ethanol and isopropanol; glycerol; glycols or glycolethers such as 2-butoxyethanol, ethylene glycol, propylene glycol,monoethyl ether and monomethyl ether of diethylene glycol, as well asaromatic alcohols such as benzyl alcohol or phenoxyethanol, analogousproducts and mixtures thereof.

The solvents are preferably present in proportions of between 1 and 40%by weight, and in particular between 5 and 30% by weight relative to thetotal weight of the composition.

The thickening agents which may be added to the compositions conformingto the invention may be chosen from sodium alginate, gum arabic,optionally crosslinked acrylic acid polymers, cellulose derivatives,heterobiopolysaccharides such as xanthan gum, inorganic thickeningagents such as bentonite may also be used. These thickening agents arepreferably present in proportions of between 0.1 and 5%, and inparticular between 0.2 and 3% by weight relative to the total weight ofthe composition.

The antioxidants which may be present in the compositions are chosen inparticular from sodium sulfite, thioglycolic acid, sodium bisulfite,dehydroascorbic acid, hydroquinone and homogentisic acid. Theseantioxidants are present in the composition in proportions of between0.05 and 1.5% by weight relative to the total weight of the composition.

These compositions may also contain other cosmetically acceptableadjuvants, such as for example penetrating agents, sequestering agents,perfumes, buffers and the like.

The compositions conforming to the invention may be provided in variousforms, such as in the form of a liquid, cream or gel or in any otherform appropriate for dyeing keratinous fibers and especially human hair.These compositions may be packaged in aerosol bottles in the presence ofa propelling agent and may form foams.

The dyeing compositions conforming to the invention containing a paraand/or ortho type oxidation dye precursor and a coupler of formula (I),are used according to a process involving developing by means of anoxidizing agent.

In conformity with this process, the dyeing composition described aboveis mixed, at the time of use, with an oxidizing solution in a sufficientquantity so as to be able to develop a color, then the mixture obtainedis applied to the keratinous fibers and in particular human hair.

The pH of the composition applied to the hair varies between 3 and 11.It is adjusted to the desired value by means of alkalinizing agents wellknown in the prior state of the art, such as ammonium hydroxide, alkalimetal carbonates, alkanolamines such as mono-, di-and triethanolamine,as well as their derivatives or sodium or potassium hydroxides, or bymeans of conventional acidifying agents such as inorganic or organicacids such as hydrochloric, tartaric, citric, phosphoric and sulfonicacids. The oxidizing solution contains, by way of oxidizing agent,hydrogen peroxide, urea peroxide, persalts such as ammonium persulfateor alkali metal bromates. A solution of hydrogen peroxide at 20 volumesis preferably used.

The mixture obtained is applied to the hair and it is allowed to act for10 to 40 minutes, preferably 15 to 30 minutes, after which the hair isrinsed, washed with shampoo, rinsed again and dried.

The coupler of formula (I) defined above may also be used in amultistage process, consisting in one of the stages, in applying theortho and/or para type oxidation dye precursor or a mixture thereof and,in another stage, in applying a dyeing composition containing thecoupler of formula (I).

The oxidizing agent may be introduced, just before the application, intothe composition applied in the second phase or alternatively applied tothe keratinous fibers themselves, in a third phase, the exposure, pH,washing and drying conditions being identical to those indicated above.

Another object of the invention consists of the new sulfur-containingmeta-phenylenediamines of formula (I) above, as well as their salts withan acid.

The subject of the invention is also the use of these sulfur-containingmeta-phenylenediamines in dyeing compositions for keratinous fibers.

The sulfur-containing meta-phenylenediamines of formula (I) or theirsalts can be prepared according to multistage processes.

According to a first process and in a first stage,bromo-2,4-dinitrobenzene is reacted, in the presence of a base such aspotassium hydroxide or potassium carbonate, with a thiol of formula (V):

    Z'-SH                                                      (V)

in which Z' represents a C₁ -C₁₈ alkyl radical, an aralkyl radical inwhich the alkyl radical corresponds to C₁ -C₆, a monohydroxy(C₁ -C₆alkyl) radical, a polyhydroxy(C₂ -C₆ alkyl) radical or a group offormula (VI) ##STR8## in which R₃ and n have the meanings indicatedabove in formula (I); and R₅ represents a hydrogen atom or a C₁ -C₃alkyl radical; in a second stage, the nitro substituents of the compoundof formula (VII): ##STR9## obtained above are reduced in order toprepare a compound corresponding to formula (VIII): ##STR10## in whichZ' has the meaning indicated above; optionally, in a third stage, anddepending on the sulfur-containing meta-phenylenediamine compound offormula (I) which it is desired to obtain, there is performed

a) either a mono-substitution of the aromatic amines in order to obtaina compound of formula (I) in which R₁ and/or R₂ are different from H

b) or an acid hydrolysis of the compound (VIII) in which Z' represents##STR11## in order to obtain the compound of formula (IX) ##STR12## inwhich R₃ and n have the meanings indicated above, R₃ however notdesignating a C₂ -C₆ acyl radical, it being possible for the nuclearamines then to be monosubstituted,

c) or a substitution of the extranuclear amine is performed beforehandon the compound of formula (VIII) in order to obtain the compound offormula (X) ##STR13## in which R₃, R₄ and n have the meanings indicatedabove, it being possible for the nuclear amines then to bemonosubstituted.

The reduction of the nitro groups of the compounds of formula (VII) ispreferably carried out using iron in acetic medium or alternatively bymeans of cyclohexene in the presence of a palladium-carbon catalyst orby any other conventional reduction process.

The substitution of the aromatic amines or of the extranuclear amine canbe carried out by reacting for example ethyl bromide, glycolbromohydrin, ethyl chloroformate, β-chloroacetamide, or aceticanhydride.

According to a second process and in a first stage, a substitutedfluoronitrobenzene of formulae (XIa) or (XIb) ##STR14## in which R'₁ andR'₂ represent a C₂ -C₆ acyl group and X represents a hydrogen atom, oralternatively R'₂ and X or R'₁ and X form, together with the nitrogenatom to which they are attached an oxazolidone ring, is reacted with athiol of formula:

    Z'-SM                                                      (XII)

in which M is an alkali metal and Z' has the meanings indicated above;in a second stage, the nitro substituent of the compound of formulae(XIIIa) or (XIIIb) ##STR15## obtained above is reduced in order toprepare a compound corresponding to the formula (XIVa) or (XIVb):##STR16## in which R'₁, R'₂ and X have the meanings indicated above;optionally, in a third stage, and depending on the sulfur-containingmeta-phenylenediamine compound of formula (I) which it is desired toobtain, a monosubstitution of the aromatic amines is performed in orderto obtain a compound of formula (I) in which R₁ and/or R₂ are differentfrom H.

Lastly, in a final stage, the compound is subjected to an acidhydrolysis so as to cut the protecting group X.

The following examples are intended to illustrate the invention without,however, being restrictive in nature.

EXAMPLE 1 Preparation of6-methylthio-1,3-di(β-hydroxy-ethylamino)benzene dihydrochloride

1st stage:

Synthesis of 6-methylthio-1,3-di(β-chlorocarbethoxyamino)benzene

14.5 ml of β-chloroethyl chloroformate are added dropwise to asuspension of 15.9 g (0.07 mole) of 6-methylthio-1,3-diaminobenzene and28 g of calcium carbonate in 12 ml of dioxane, heated in a boiling waterbath.

After heating for 30 min, this suspension is poured into 500 ml of icecold water acidified with 60 ml of a concentrated hydrochloric acidsolution.

An oil crystallizes.

It is drained, reimpasted in water and dried at 45° C. over phosphoricanhydride and under vacuum.

White crystals (24.4 g) are obtained which, after recrystallization fromisopropanol, melt at 119° C. and whose elemental analysis calculated forC₁₃ H₁₆ N₂ O₄ SCl₂ is:

    ______________________________________                                        Analysis C      H        N    O      S    Cl                                  ______________________________________                                        Theory % 42.52  4.39     7.63 17.43  8.73 19.31                               Found %  42.72  4.48     7.61 17.54  8.61 19.24                               ______________________________________                                    

2nd stage:

Alkaline hydrolysis

The compound obtained in the 1st stage (22.8 g 0.062 mole) is suspendedin 54 ml of 96% ethanol, 27 ml of water and 54 ml of 10N caustic soda.

The suspension is heated at the reflux temperature of the alcohol untilcomplete hydrolysis (10 min) of the oxazolidone intermediate isobtained.

The reaction is monitored by thin-layer chromatography (silica gel;eluant: ethyl acetate).

The alcohol is evaporated under reduced pressure, a brown oil isobtained in suspension to which 100 ml of ice cold water are added andthe mixture is extracted with ethyl ether (about 500 ml).

The ethereal phase is dried over sodium sulfate and filtered. 20 ml ofan approximately 7N hydrochloric acid solution in absolute ethanol areadded thereto.

The dihydrochloride precipitates as oil which crystallizes.

After draining, washing with ethyl ether and drying over potassiumhydroxide, white crystals (18.4 g) are obtained which melt withdecomposition at 158°-160° C. and whose elemental analysis calculatedfor C₁₁ H₂₀ N₂ O₂ SCl₂ is:

    ______________________________________                                        Analysis C      H        N    O      S    Cl                                  ______________________________________                                        Theory % 41.91  6.39     8.89 10.15  10.17                                                                              22.49                               Found %  41.89  6.42     8.90 10.27  10.08                                                                              22.58                               ______________________________________                                    

EXAMPLE 2 Preparation of 6-methylthio-1-N-β-hydroxyethyl-amino-3-aminobenzene.

1st stage:

Synthesis of 6-methylthio-3-acetylaminonitrobenzene

At room temperature, 50.0 g of sodium thiomethoxide are suspended in 500ml of dimethoxyethane and 99.1 g (0.5 mole) of2-nitro-4-acetylaminofluorobenzene are added, in portions, over 30 min,while the temperature is maintained between 25° and 27° C. by means ofan ice cold water bath.

After leaving to stir for an additional 30 min at 25°-27° C., thissuspension is poured into 4 liters of ice cold water.

The orange-yellow crystallized precipitate is drained, reimpasted inwater and dried over phosphoric anhydride.

107.0 g of orange crystals are obtained which melt at 178° C. afterrecrystallization from 96% ethanol, and whose elemental analysiscalculated for C₉ H₁₀ N₂ O₃ S is:

    ______________________________________                                        Analysis  C         H      N       O    S                                     ______________________________________                                        Theory %  47.78     4.45   12.38   21.21                                                                              14.17                                 Found %   47.90     4.40   12.48   21.01                                                                              14.10                                 ______________________________________                                    

2nd stage:

Synthesis of 6-methylthio-3-acetylamino-1-aminobenzene.

A suspension of 0.5 g of ammonium chloride and 17 g of zinc in the formof a fine powder in 40 ml of 96% ethanol and 3.6 ml of water is heatedat the reflux temperature of the alcohol.

6.8 g (0.03 mole) of the compound obtained during the 1st stage areadded in portions so as to maintain the reflux without heating (anexothermic decolorization is observed).

After the end of the addition, the reflux is maintained for 20 min.

The mixture is filtered in the boiling state and the zinc slurry iswashed with minimum hot alcohol.

The filtrate is diluted with two volumes of ice cold water.

The expected compound crystallizes slowly.

After draining, washing with water, drying over phosphoric anhydride andrecrystallization from isopropanol, 2.6 g of white crystals are obtainedwhich melt at 105° C. and whose elemental analysis calculated for C₉ H₁₂N₂ OS is:

    ______________________________________                                        Analysis  C         H      N       O    S                                     ______________________________________                                        Theory %  55.08     6.16   14.27   8.15 16.34                                 Found %   55.07     6.18   14.11   8.32 16.31                                 ______________________________________                                    

3rd stage

Synthesis of6-methylthio-1β-chlorocarbethoxy-amino-3-acetylaminobenzene.

This compound is prepared according to the procedure described inExample 1 (1st stage).

White crystals are obtained which, after recrystallization from ethylacetate, have a melting point of 162° C. and whose elemental analysiscalculated for C₁₂ H₁₅ N₂ O₃ SCl is:

    ______________________________________                                        Analysis C      H        N    O      S    Cl                                  ______________________________________                                        Theory % 47.60  4.99     9.25 15.85  10.59                                                                              11.71                               Found %  47.76  5.07     9.05 16.05  10.43                                                                              11.60                               ______________________________________                                    

4th stage

Alkaline hydrolysis

The alkaline hydrolysis of the compound obtained in the preceding stageis carried out according to the procedure described in Example 1 (2ndstage).

After recrystallization from acetonitrile, a white crystalline compoundis obtained with a yield of 69%, whose melting point is 96° C. and whoseelemental analysis calculated for C₉ H₁₄ N₂ OS is:

    ______________________________________                                        Analysis  C         H      N       O    S                                     ______________________________________                                        Theory %  54.52     7.12   14.13   8.07 16.17                                 Found %   54.60     7.16   14.11   8.20 15.98                                 ______________________________________                                    

EXAMPLE 3 Preparation of 6-methylthio-3-N-β-hydroxyethy-aminoanilinedihydrochloride.

1st stage

Synthesis of 3-(4-methylsulfanyl-3-nitrophenyl)-oxazolidin-2-one.

The procedure described in Example 1 (1st stage) is used.

Starting with 45.2 g (0.2 mole) of3-(4-fluoro-3-nitrophenyl)oxazolidin-2-one, 48.5 g of orange crystalsare obtained which, after recrystallization from dimethoxyethane, have amelting point of 180° C. and whose elemental analysis calculated for C₁₀H₁₀ N₂ O₄ S is:

    ______________________________________                                        Analysis  C         H      N       O    S                                     ______________________________________                                        Theory %  47.24     3.96   11.02   25.17                                                                              12.61                                 Found %   47.20     3.99   11.06   25.43                                                                              12.49                                 ______________________________________                                    

2nd stage:

Synthesis of 6-methylthio-3-N-β-hydroxyethyl-aminonitrobenzene.

The alkaline hydrolysis of the preceding compound is carried outaccording to the procedure described in Example 1 (2nd stage).

Dark red crystals are obtained with a yield of 83% whose melting pointis 104° C. and whose elemental analysis calculated for C₉ H₁₂ N₂ O₃ Sis:

    ______________________________________                                        Analysis  C         H      N       O    S                                     ______________________________________                                        Theory %  47.36     5.30   12.27   21.03                                                                              14.05                                 Found %   47.34     5.38   12.34   21.20                                                                              13.89                                 ______________________________________                                    

3rd stage

The reduction of the preceding compound is carried out according to theprocedure used for Example (2nd stage).

The dihydrochloride crystallizes from the reaction medium filtered afteraddition of hydrochloric absolute ethanol.

White crystals are obtained which melt with decomposition at 154°-157°C. and whose elemental analysis calculated for C₉ H₁₆ N₂ OSCl₂ is:

    ______________________________________                                        Analysis C      H        N    O      S    Cl                                  ______________________________________                                        Theory % 39.86  5.95     10.30                                                                              5.90   11.82                                                                              26.14                               Found %  39.92  6.05     10.32                                                                              6.10   11.66                                                                              25.98                               ______________________________________                                    

EXAMPLE 4 Preparation of 6-(β-acetylaminoethylthio)-1,3-diaminobenzenedihydrochloride

1st stage

Synthesis of 6-(β-acetylaminoethylthio)-3-nitro-1-acetylaminobenzene.

20 g of powdered potassium hydroxide are dissolved in a solution of 71.4g (0.6 mole) of β-acetylaminoethylthiol in 300 ml of dimethoxyethaneheated to 45° C.

After cooling to 30° C., 47.5 g (0.24 mole) of2-acetylamino-4-nitrofluorobenzene are added in portions, over 30 min.

The suspension is kept at 30°-35° C. for 30 min.

The reaction medium is poured into 800 ml of ice cold water. The yellowcrystalline precipitate is drained, reimpasted in water and dried overphosphoric anhydride.

Yellow crystals (67.3 g) are obtained which, after recrystallizationfrom ethanol, melt at 172° C. and whose elemental analysis calculatedfor C₁₂ H₁₅ N₃ O₄ S is

    ______________________________________                                        Analysis  C         H      N       O    S                                     ______________________________________                                        Theory %  48.48     5.09   14.13   21.52                                                                              10.78                                 Found %   48.69     5.16   14.00   21.74                                                                              10.80                                 ______________________________________                                    

2nd stage

Synthesis of 6-(β-acetylaminoethylthio)-3-amino1-acetylaminobenzene.

The reduction is carried out according to the procedure described forExample 2 (2nd stage). A white crystalline compound is obtained whosemelting point is 148° C. and whose elemental analysis calculated for C₁₂H₁₇ N₃ O₂ S is:

    ______________________________________                                        Analysis  C         H      N       O    S                                     ______________________________________                                        Theory %  53.91     6.41   15.72   11.97                                                                              11.99                                 Found %   53.95     6.39   15.90   12.08                                                                              11.95                                 ______________________________________                                    

3rd stage

The deacetylation of the amino group in position 1 is carried out byheating, at 80° C. for 5 hours, a solution of 20 g (0.74 mole) of thecompound obtained in the preceding stage in 300 ml of a normalhydrochloric acid solution.

The mixture is cooled and neutralized with a 20% ammonium hydroxidesolution.

After extraction with ethyl acetate, drying over sodium sulfate,filtration and evaporation to dryness, the oil obtained and purified bypassing over a medium-pressure column (silica gel - eluant: mixture ofethyl and heptane). The dihydrochloride is prepared in hydrochloricabsolute ethanol and precipitated by diluting with ethyl ether. Themixture is drained and dried over potassium hydroxide.

The white crystals (4.7 g) melt with decomposition at 201°-204° C. Themass spectrum is in conformity with the expected product.

EXAMPLES OF DYEING PROCESSES

    ______________________________________                                        Composition A                                                                 ______________________________________                                        Octyl dodecanol sold under the name                                                                     8.0    g                                            EUTANOL D by the company HENKEL                                               Oleic acid                20.0   g                                            Monoethanolamine lauryl ether sulfate                                                                   3.0    g                                            sold under the name SIPON LM 35 by the                                        company HENKEL                                                                Ethyl alcohol             10.0   g                                            Benzyl alcohol            10.0   g                                            Cetylstearyl alcohol containing                                                                         2.4    g                                            33 moles of ethylene oxide sold under                                         the name SIMULSOL GS by the company                                           SEPPIC                                                                        Ethylenediaminetetraacetic acid                                                                         0.2    g                                            Aqueous solution containing 60% of                                                                      3.7    g AI                                         AI of a cationic polymer having the                                           following recurring unit:                                                      ##STR17##                                                                    Monoethanolamine          7.5    g                                            Linoleic acid diethanolamide sold under                                                                 8.0    g                                            the name COMPERLAN F by the company                                           HENKEL                                                                        Ammonium hydroxide containing 20% NH.sub.3                                                              10.2   g                                            Sodium metabisulfite in aqueous                                                                         1.3    g                                            solution at 35%                                                               Hydroquinone              0.15   g                                            Dyes                      x      g                                            Demineralized water   qs  100.0  g                                            ______________________________________                                    

Composition B

Hydrogen peroxide at 20 volumes and at pH=3.

Dyeing procedure

The composition A is mixed, weight for weight, with the composition B.The mixture obtained is applied to natural gray hair which is 90% white,permanently waved or otherwise, for 30 min. The hair is then rinsed,washed with shampoo and then rinsed again and dried.

    ______________________________________                                                       EXAMPLES                                                                      1     2       3       4                                        ______________________________________                                        (in g)                                                                        Composition A containing:                                                     6-methylthio-3-N-β-hydroxy-                                                               0.54                                                         ethylaminoaniline, dihydro-                                                   chloride                                                                      6-methylthio-1-N-β-hydroxy-                                                                       0.40                                                 ethylamino-3-aminobenzene                                                     6-methylthio-1,3-di(β-hydroxy-                                                                            0.63                                         ethylamino)benzene, dihydro-                                                  chloride                                                                      6-(β-acetylaminoethylthio)-1,3-   0.60                                   diaminobenzene, dihydro-                                                      chloride                                                                      Para-phenylenediamine                                                                          0.22    0.22    0.22  0.22                                   Mixture of A and B                                                            weight for weight                                                             pH of the mixture                                                                              10.2    10.3    10.5  10.3                                   Shades obtained                                                               On natural gray hair     bluish- pearly                                       which is 90% white       gray    gray                                         On permanently waved natural                                                                   intense               ash                                    gray hair which is 90% white                                                                   pearly                blond                                                   ashen                                                        ______________________________________                                    

    ______________________________________                                        Composition A                                                                 ______________________________________                                        Polyglycerolated oleyl alcohol containing                                                               4.0    g                                            2 moles of glycerol                                                           Polyglycerolated oleyl alcohol containing                                                               5.69   g AI                                         4 moles of glycerol containing 78% of AI                                      Oleic acid                3.0    g                                            Oleylamine containing 2 moles of                                                                        7.0    g                                            ethylene oxide sold under the name                                            ETHOMEEN 012 by the company AKZO                                              Diethylaminopropyl lauryl amino-                                                                        3.0    g AI                                         succinamate, sodium salt, containing                                          55% of AI                                                                     Oleyl alcohol             5.0    g                                            Oleic acid diethanolamide 12.0   g                                            Propylene glycol          3.5    g                                            Ethyl alcohol             7.0    g                                            Dipropylene glycol        0.5    g                                            Propylene glycol monomethyl ether                                                                       9.0    g                                            Sodium metabisulfite in aqueous                                                                         0.455  g                                            solution at 35%                                                               Ammonium acetate          0.8    g                                            Antioxidant, sequestrant                                                                       qs                                                           Perfume, preservatives                                                                         qs                                                           Monoethanolamine qs pH 9.8                                                    Dyes                          x      g                                        Demineralized water                                                                            qs           100.0  g                                        ______________________________________                                    

Composition B

It consists of a solution of hydrogen peroxide at 20 volumes whose pH isadjusted to between 1 and 1.5 with orthophosphoric acid.

Dyeing procedure

The composition A is mixed, weight for weight, with the composition B ofhydrogen peroxide. The mixture obtained is applied to natural gray hairwhich is 90% white, permanently waved or otherwise, for 30 minutes. Thehair is then rinsed, washed with shampoo, then rinsed again and dried.

    __________________________________________________________________________                      EXAMPLES                                                                      5    6   7    8    9                                        __________________________________________________________________________    (in g)                                                                        Composition A containing:                                                     6-methylthio-3-N-β-hydroxy-                                                                0.81                                                        ethylaminoaniline, dihydrochloride                                            6-methylthio-1,3-diaminobenzene,                                                                     0.68                                                   dihydrochloride                                                               6-methylthio-1-N-β-hydroxy-                                                                         0.59                                               ethylamino-3-aminobenzene                                                     6-methylthio-1,3-di(β-hydroxy-                                                                           0.95                                          ethylamino)benzene, dihydrochloride                                           6-(β-acetylaminoethylthio)-1,3- 1.19                                     diaminobenzene, dihydrochloride                                               2,6-dimethylparaphenylenediamine                                                                0.41 0.41                                                                              0.41 0.41 0.54                                     Mixture of A and B                                                            weight for weight                                                             pH of the mixture 6.2  6.2 6.5  6.2  6.0                                      Shades obtained                                                               On natural gray hair   intense  ash blue                                                                           peacock                                  which is 90% white     blue          blue                                     On permanently waved natural                                                                    intense  ash blue                                           gray hair which is 90% white                                                                    ash blue                                                    __________________________________________________________________________

We claim:
 1. A composition for dyeing human hair comprising, in avehicle suitable for dyeing said human hair,(a) at least one couplercomprising a sulfur-containing meta-phenylenediamine having the formula##STR18## wherein Z represents C₁ -C₁₈ alkyl, aralkyl wherein the alkylmoiety has 1-6 carbon atoms, C₁ -C₆ monohydroxyalkyl, C₂ -C₆polyhydroxyalkyl, aryl, aminoalkyl having the formula ##STR19## whereinn is an integer ranging from 1 to 6 and R₃ and R₄, each independently,represent hydrogen, C₁ -C₄ alkyl, C₁ -C₄ hydroxyalkyl or C₂ -C₆ acyl; R₁and R₂, each independently, represent hydrogen, C₁ -C₆ alkyl, C₁ -C₆monohydroxyalkyl, C₂ -C₆ polyhydroxyalkyl, C₁ -C₆ monocarbamylalkyl, C₁-C₆ dicarbamylalkyl, C₁ -C₆ aminoalkyl, C₂ -C₆ acyl, C₂ -C₆ carbalkoxy,carbamyl or mono(C₁ -C₆)alkyl carbamyl, with the proviso that R₁ and R₂do not simultaneously represent hydrogen when Z represents alkyl orhydroxyalkyl; or an acid addition salt of said sulfur-containingmetaphenylenediamine of formula (I); said sulfur-containingmeta-phenylenediamine being present in an amount ranging from 0.05 to3.5 percent by weight based on the total weight of said composition; and(b) at least one of an ortho or para oxidation dye precursor present inan amount effective to dye said human hair by oxidative condensationreaction between said precursor and said coupler.
 2. The composition ofclaim 1 wherein said ortho or para oxidation dye precursor is selectedfrom the group consisting of a para-phenylenediamine, apara-aminophenol, a para heterocyclic precursor derived from pyridine orpyrimidine, an orthoaminophenol and a bis-phenylalkylenediamine.
 3. Thecomposition of claim 1 wherein Z represents methyl, ethyl, propyl,butyl, dodecyl, hexadecyl, benzyl, phenyl, --CH₂ CH₂ --OH, --CH₂--CHOH--CH₂ --OH, --CH₂ --CHOH--CH₃, --CH₂ --CH₂ NH₂, --CH₂ --CH₂--NHCH₃, ##STR20## --CH₂ --CH₂ --NH--COCH₃ ; and R₁ or R₂ represents anacyl radical selected from the group consisting of formyl, acetyl andpropionyl.
 4. The composition of claim 1 wherein said sulfur-containingmeta-phenylenediamine of formula (I) is selected from the groupconsisting of6-methylthio-di-(β-hydroxyethylamino)benzene,6-methylthio-1-N-β-hydroxyethylamino-3-aminobenzene,6-(β-acetylaminoethylthio)-1,3-diaminobenzene,6-methylthio-3-N-β-hydroxyethylaminoaniline,6-(β-acetylaminoethylthio)-3-amino-1-acetylaminobenzene,6-methylthio-3-acetylaminoaniline,6-(β-acetylaminoethylthio)-3-acetylaminoaniline and an acid additionsalt thereof.
 5. The composition of claim 1 wherein said acid additionsalt is a hydrochloride, a sulfate or a hydrobromide.
 6. The compositionof claim 1 which also includes a further coupler selected from the groupconsisting of a meta-diphenol, a meta-aminophenol, ameta-phenylenediamine other than the sulfur-containingmeta-phenylenediamine of formula (I), a meta-acylaminophenol, ameta-ureidophenol, a meta-carbalkoxyaminophenol, α-naphthol, an indolederivative and a coupler possessing an active methylene group, andwherein said ortho or para oxidation dye precursor and said coupler offormula I and said further coupler are present in a total amount rangingfrom 0.3 to 7 percent by weight based on the total weight of saidcomposition.
 7. The composition of claim 1 which also includes at leastone of(a) a cationic, anionic, nonionic or amphoteric surface activeagent, or a mixture thereof, present in an amount ranging from 0.5 to 55percent by weight based on the total weight of said composition; (b) anorganic solvent present in an amount ranging from 1 to 40 percent byweight based on the total weight of said composition; (c) a thickeningagent present in an amount ranging from 0.1 to 5 percent by weight basedon the total weight of said composition; and (d) an antioxidant presentin an amount ranging from 0.05 to 1.5 percent by weight based on thetotal weight of said composition.
 8. The composition of claim 1 in theform of a liquid, a cream, a gel or an aerosol.
 9. A method for dyeinghuman hair comprising the steps of:(a) admixing at the time of dyeingsaid human hair (i) a composition comprising, in a medium suitable fordyeing said human hair, a sulfur-containing meta-phenylenediamine havingthe formula ##STR21## wherein Z represents C₁ -C₁₈ alkyl, aralkylwherein the alkyl moiety has 1-6 carbon atoms, C₁ -C₆ monohydroxyalkyl,C₂ -C₆ polyhydroxyalkyl, aryl, aminoalkyl having the formula ##STR22##wherein n is an integer ranging from 1 to 6 and R₃ and R₄, eachindependently, represent hydrogen, C₁ -C₄ alkyl, C₁ -C₄ hydroxyalkyl orC₂ -C₆ acyl; R₁ and R₂, each independently, represent hydrogen, C₁ -C₆alkyl, C₁ -C₆ monohydroxyalkyl, C₂ -C₆ polyhydroxyalkyl, C₁ -C₆monocarbamylalkyl, C₁ -C₆ dicarbamylalkyl, C₁ -C₆ aminoalkyl, C₂ -C₆acyl, C₂ -C₆ carbalkoxy, carbamyl or mono(C₁ -C₆)alkyl carbamyl, withthe proviso that R₁ and R₂ do not simultaneously represent hydrogen whenZ represents alkyl or hydroxyalkyl; or an acid addition salt of saidsulfur-containing meta-phenylenediamine of formula (I); saidsulfur-containing meta-phenylenediamine being present in an amountranging from 0.05 to 3.5 percent by weight based on the total weight ofsaid composition; and at least one of an ortho or para oxidation dyeprecursor present in an amount effective to dye said human hair byoxidative condensation reaction between said precursor and said coupler,said composition not containing metal ions, with (ii) an oxidizingsolution in an amount sufficient so as to develop a color on said humanhair, the resulting composition having a pH ranging from 3 to 11; and(b) applying to said hair the hair dye composition resulting from step(a).
 10. The method of claim 9 wherein said hair dye composition appliedto said hair in step (b) is permitted to remain in contact with saidhair for a period of time ranging from 10 to 40 minutes at which timesaid method includes rinsing the hair, shampooing the hair, rinsing thehair and drying the hair.
 11. The method of claim 9 wherein said hairdye composition applied to said hair in step (b) is permitted to remainin contact with said hair for a period of time ranging from 15 to 30minutes at which time said method includes rinsing the hair, shampooingthe hair, rinsing the hair and drying the hair.
 12. A method for theoxidative dyeing of human hair comprising:in a first step applying tosaid hair an ortho or para oxidation dye precursor present in a mediumsuitable for dyeing said hair and in an amount effective to dye saidhair by oxidative condensation reaction between said precursor and acoupler; and in a second step applying to said hair a compositioncomprising in a medium suitable for dyeing said hair a sulfur-containingmeta-phenylenediamine coupler having the formula ##STR23## wherein Zrepresents C_(1-C) ₁₈ alkyl, aralkyl wherein the alkyl moiety has 1-6carbon atoms, C₁ -C₆ monohydroxyalkyl, C₂ -C₆ polyhydroxyalkyl, aryl,aminoalkyl having the formula ##STR24## wherein n is an integer rangingfrom 1 to 6 /and R₃ and R₄, each independently, represent hydrogen, C₁-C₄ alkyl, C₁ -C₄ hydroxyalkyl or C₂ -C₆ acyl; R₁ and R₂, eachindependently, represent hydrogen, C₁ -C₆ alkyl, C₁ -C₆monohydroxyalkyl, C₂ -C₆ polyhydroxyalkyl, C₁ -C₆ monocarbamylalkyl, C₁-C₆ dicarbamylalkyl, C₁ -C₆ aminoalkyl, C₂ -C₆ acyl, C₂ -C₆ carbalkoxy,carbamyl or mono(C₁ -C₆)alkylcarbamyl, with the proviso that R₁ and R₂do not simultaneously represent hydrogen when Z represent alkyl orhydroxyalkyl; or an acid addition salt of said sulfur-containingmeta-phenylenediamine of formula (I); said sulfur-containingmeta-phenylenediamine being present in an amount ranging from 0.05 to3.5 percent by weight based on the total weight of said composition;said coupler containing composition applied to said hair in said secondstep optionally containing an oxidizing agent present in an amounteffective to develop color on said hair; or in the alternative, in athird step applying to said hair a composition comprising in a mediumsuitable for dyeing said hair an oxidizing agent present in an amounteffective to develop color on said hair.
 13. The method of claim 12wherein the composition applied to said hair in said first, second andalternatively third step is permitted to remain in contact with the saidhair for a period of time ranging from 10 to 40 minutes, at which timesaid method includes rinsing the hair, shampooing the hair, rinsing thehair and drying the hair.
 14. The method of claim 12 wherein thecomposition applied to the hair in said first, second and alternativelythird steps is permitted to remain in contact with said hair for aperiod of time ranging from 15 to 30 minutes at which time said methodincludes rinsing the hair, shampooing the hair, rinsing the hair anddrying the hair.
 15. A composition for dyeing human hair comprising, ina vehicle suitable for dyeing said human hair,(a) at least one couplercomprising a sulfur-containing meta-phenylenediamine having the formula##STR25## wherein Z represents a member selected from the groupconsisting of methyl, ethyl, propyl, butyl, dodecyl, hexadecyl, benzyl,phenyl, --CH₂ CH₂ --OH, --CH₂ --CHOH--CH₂ --OH, --CH₂ --CHOH--CH₃, --CH₂--CH₂ NH₂, --CH₂ --CH₂ --NHCH₃, ##STR26## --CH₂ --CH₂ --NH--COCH₃ ; R₁and R₂, each independently, represent hydrogen, C_(1-C) ₆ alkyl, C_(1-C)₆ monohydroxyalkyl, C₂ -C₆ polyhydroxyalkyl, C₁ -C₆ monocarbamylalkyl,C₁ -C₆ dicarbamylalkyl, C₁ -C₆ aminoalkyl, C₂ -C₆ acyl, C₂ -C₆carbalkoxy, carbamyl or mono (C₁ -C₆) alkyl carbamyl with the provisothat at least one of R₁ or R₂ represents an acyl radical selected fromthe group consisting of formyl, acetyl and propionyl; or an acidaddition salt of said sulfur-containing metaphenylenediamine of formula(I); said sulfur-containing meta-phenylenediamine being present in anamount ranging from 0.05 to 3.5 percent by weight based on the totalweight of said composition; and (b) at least one of an ortho or pareoxidation dye precursor present in an amount effective to dye said humanhair by oxiderive condensation reaction between said precursor and saidcoupler.
 16. The composition of claim 15 wherein said ortho or paraoxidation dye precursor is selected from the group consisting of apara-phenylenediamine, a para-aminophenol, a pare heterocyclic precursorderived form pyridine or pyrimidine, an orthoaminophenol and abis-phenylalkylenediamine.
 17. The composition of claim 15 wherein saidacid addition salt is a hydrochloride, a sulfate or a hydrobromide. 18.The composition of claim 15 which also includes a further couplerselected from the group consisting of a metadiphenol a metaaminophenol ametaphenylenediamine other than the sulfur-containingmetaphenylenediamine of formula (I), a metaacylaminophenol, ametaureidophenol, a metacarbalkoxyaminophenol, α-naphthol, an indolederivative and a coupler possessing an active methylene group, andwherein said ortho or pars oxidation dye precursor and said coupler offormula I and said further coupler are present in a total amount rangingfrom 0.3 to 7 percent by weight based on the total weight of saidcomposition.
 19. The composition of claim 15 which also includes atleast one of(a) a cationic, anionic, nonionic or amphoteric surfaceactive agent, or a mixture thereof, present in an amount ranging from0.5 to 55 percent by weight based on the total weight of saidcomposition; (b) an organic solvent present in an amount ranging from 1to 40 percent by weight based on the total weight of said composition;(c) a thickening agent present in an amount ranging from 0.1 to 5percent by weight based on the total weight of said composition; and (d)an antioxidant present in an amount ranging from 0.05 to 1.5 percent byweight based on the total weight of said composition.
 20. Thecomposition of claim 15 in the form of a liquid, a cream, a gel or anaerosol.
 21. A method for dyeing human hair comprising the steps of:(a)admixing at the time of dyeing said human hair (i) a compositioncomprising, in a medium suitable for dyeing said human hair, asulfur-containing meta-phenylenediamine having the formula ##STR27##wherein Z represents a member selected from the group consisting ofmethyl, ethyl, propyl, butyl, dodecyl, hexadecyl, benzyl, phenyl, --CH₂CH₂ --OH, --CH₂ --CHOH--CH₂ --OH, --CH₂ --CHOH--CH₃, --CH₂ --CH₂ NH₂,--CH_(2--CH) ₂ --CH₂ --NHCH₃, ##STR28## --CH₂ --CH₂ --NH--COCH₃ ; R₁ andR₂ , each independently, represent hydrogen, C₁ -C₆ alkyl, C₁ -C₆monohydroxyalkyl, C₂ -C₆ polyhydroxyalkyl, C₁ -C₆ monocarbamylalkyl, C₁-C₆ dicarbamylalkyl, C₁ -C₆ aminoalkyl, C₂ -C₆ acyl, C₂ -C₆ carbalkoxy,carbamyl or mono (C₁ -C₆) alkyl carbamyl with the proviso that at leastone of R₁ or R₂ represents an acyl radical selected from the groupconsisting of formyl, acetyl and propionyl; or an acid addition salt ofsaid sulfur-containing meta-phenylenediamine of formula (I); saidsulfur-containing meta-phenylenediamine being present in an amountranging from 0.05 to 3.5 percent by weight based on the total weight ofsaid composition; and at least one of an ortho or para oxidation dyeprecursor present in an amount effective to dye said human hair byoxidative condensation reaction between said precursor and said coupler,said composition not containing metal ions, with (ii) an oxidizingsolution in an amount sufficient so as to develop a color on said humanhair, the resulting composition having a pH ranging from 3 to 11; and(b) applying to said hair the hair dye composition resulting from step(a).
 22. The method of claim 21 wherein said hair dye compositionapplied to said hair in step (b) is permitted to remain in contact withsaid hair for a period of time ranging from 10 to 40 minutes at whichtime said method includes rinsing the hair, shampooing the hair, rinsingthe hair and drying the hair.
 23. The method of claim 21 wherein saidhair dye composition applied to said hair in step (b) is permitted toremain in contact with said hair for a period of time ranging from 15 to30 minutes at which time said method includes rinsing the hair,shampooing the hair, rinsing the hair and drying the hair.
 24. A methodfor the oxidative dyeing of human hair comprising:in a first stepapplying to said hair an ortho or para oxidation dye precursor presentin a medium suitable for dyeing said hair and in an amount effective todye said hair by oxidative condensation reaction between said precursorand a coupler; and in a second step applying to said hair a compositioncomprising in a medium suitable for dyeing said hair a sulfurcontainingmeta-phenylenediamine coupler having the formula ##STR29## wherein Zrepresents a member selected from the group consisting of methyl, ethyl,propyl, butyl, dodecyl, hexadecyl, benzyl, phenyl, --CH₂ CH₂ --OH, --CH₂--CHOH--CH₂ --OH, --CH₂ --CHOH--CH₃, --CH₂ --CH₂ NH₂, --CH₂ --CH₂--NHCH₃, ##STR30## and --CH₂ --CH₂ --NH--COCH₃ ; R₁ and R₂, eachindependently, represent hydrogen, C₁ -C₆ alkyl, C₁ -C₆monohydroxyalkyl, C₂ -C₆ polyhydroxyalkyl, C₁ -C₆ monocarbamylalkyl, C₁-C₆ dicarbamylalkyl, C₁ -C₆ aminoalkyl, C₂ -C₆ acyl, C₂ -C₆ carbalkoxy,carbamyl or mono (C₁ -C₆) alkyl carbamyl with the proviso that at leastone of R₁ or R₂ represents an acyl radical selected from the groupconsisting of formyl, acetyl and propionyl; or an acid addition salt ofsaid sulfur-containing meta-phenylenediamine of formula (I); saidsulfur-containing meta-phenylenediamine being present in an amountranging from 0.05 to 3.5 percent by weight based on the total weight ofsaid composition; said coupler containing composition applied to saidhair in said second step optionally containing an oxidizing agentpresent in an amount effective to develop color on said hair; or in thealternative, in a third step applying to said hair a compositioncomprising in a medium suitable for dyeing said hair an oxidizing agentpresent in an amount effective to develop color on said hair.
 25. Themethod of claim 24 wherein the composition applied to said hair in saidfirst, second and alternatively third step is permitted to remain incontact with the said hair for a period of time ranging from 10 to 40minutes, at which time said method includes rinsing the hair, shampooingthe hair, rinsing the hair and drying the hair.
 26. The method of claim24 wherein the composition applied to the hair in said first, second andalternatively third steps is permitted to remain in contact with saidhair for a period of time ranging from 15 to 30 minutes at which timesaid method includes rinsing the hair, shampooing the hair, rinsing thehair and drying the hair.